Last night’s serious incident involving an Emirates A345 departing Melbourne for Dubai as flight EK 407 has caused some very striking images to be posted on the industry site Pprune.org and in the general media.
The jet rotated to an abnormally nose high attitude causing what is known as a ‘tail strike.’ There are reports of up to three tail strikes in succession. This particular tail strike or strikes left metal strewn for tens of metres along the runway, and shows that a considerable portion of the lower fuselage that curves upwards under the tail made unintended contact with the runway at high speed.
The tail strike or strikes occurred at a velocity and airframe loading (fuelled for a 14 hour 45 minute flight) where it would not have been possible to abort the take off without exposing those on board to the extreme perils of an undercarriage failure and/or crashing through the perimeter of the airport.
However after the tail strike the jet gained so little altitude that with its nose still high it struck and damaged landing lights or other objects at the end of the runway.
According to some reports, objects only 150 cms high were struck by the rear of the jet and a jet blast pattern was visible in the grass to either side of the path of the A345.
The Airbus gradually gained a safe altitude, and remained controllable and the pilots began dumping some fuel over Port Philip before making what was reported as a nevertheless overweight emergency landing at the airport.
Reports of smoke and a smell of burning in the cabin were with little doubt the factors in making a decision to land much sooner than it would taken to reduce the weight of the airliner to the maximum limit for a touch down.
A passenger on the flight says that one of the pilots subsequently said he believed some cargo may have shifted during the take off roll. As the A345 has a tail altimeter intended to prevent such incidents this comment may be an important insight into why such a tail strike protection system didn’t kick in.
But as is always the case with serious incidents, there can be many early clues as to what might have happened that can only be verified or discarded in the course of the investigation which the ATSB has already begun.
An ATSB source is reported as saying that ‘long airliners’ are at risk from tail strikes. In fact the A345 is not proportionately long at all, which suggests that the source may have been thinking about the truly long version of this jet, the A340-600 (or A346).